2 Replies to “What nata means for you”

  1. Another question from me out in the peanut gallery…
    Has the ATA code grown anything like the “disk-level transaction clustering” patch being experimented with on NetBSD a few years ago?

    http://kerneltrap.org/node/410
    http://www.blasted-heath.com/nbsd/cluster/

    I questioned that at the time (as one of the anonymous cowards in the Kerneltrap thread, no less), but that was before I discovered the areal density of a cheap 120+GB ATA drive with no support for command queuing absolutely stomps any possible benefit from TCQ with older drives on a ‘plain old’ UWSCSI bus. On a single-user desktop, anyway.

    On top of that, I now I realize I may’ve misunderstood the thing and it may only be clustering transactions that were already contiguous, but I’m not doing a good job of actually reading the code while trying to get out the door for work. :}

    [I do have time to notice that Storagereview.com’s “IOMeter File Server – 64 I/O in IO/Sec” test actually shows a difference between TCQ/NCQ and no queueing, though I also can’t tell if the scores are in any particular real-life units.]

  2. Another question from me out in the peanut gallery…
    Has the ATA code grown anything like the “disk-level transaction clustering” patch being experimented with on NetBSD a few years ago?

    http://kerneltrap.org/node/410
    http://www.blasted-heath.com/nbsd/cluster/

    I questioned that at the time (as one of the anonymous cowards in the Kerneltrap thread, no less), but that was before I discovered the areal density of a cheap 120+GB ATA drive with no support for command queuing absolutely stomps any possible benefit from TCQ with older drives on a ‘plain old’ UWSCSI bus. On a single-user desktop, anyway.

    On top of that, I now I realize I may’ve misunderstood the thing and it may only be clustering transactions that were already contiguous, but I’m not doing a good job of actually reading the code while trying to get out the door for work. :}

    [I do have time to notice that Storagereview.com’s “IOMeter File Server – 64 I/O in IO/Sec” test actually shows a difference between TCQ/NCQ and no queueing, though I also can’t tell if the scores are in any particular real-life units.]

    Now watch as I quite probably post this twice. :P

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